Flore et feux dans une mosaïque de forêts et de savanes anciennes d'Afrique centrale : Check‐list du Parc National des Plateaux Batéké (Gabon)

RESUME Contexte et buts – Les savanes anciennes d'Afrique sont influencées par les feux, possèdent des suffrutices géoxyliques et endémiques et elles sont encore peu étudiées. Le présent article est une étude du Parc National des Plateaux Batéké (PNPB) au Gabon et de l'incidence des feux sur sa flore en vue de comprendre s'il constitue une savane ancienne Il présente 1) une check-liste des plantes vasculaires, y compris des espèces endémiques et des suffrutices géoxyliques et 2) une analyse de l'incidence des feux sur la flore de la savane herbacée suivie de recommandations relatives à la lutte contre les feux en vue de promouvoir la diversité végétale. Matériau et méthodes – 1,914 collections botaniques constituées de 2001 à 2019 par les auteurs (de la présente étude) et d'autres étaient extraites des bases de données des MO et des NHN en 2021 pour créer la check-list. L'incidence des feux a été étudiée travers un inventaire sur trois saisons, des herbacées et des suffrutices géoxyliques effectué sur des parcelles dans cinq zones d'étude situées à 600 m d'altitude et brulée tous les ans en saison sèche. Une analyse de variance à deux facteurs a été effectuée à travers deux traitements de brûlages et des traitements sur trois saisons. Principaux résultats – La zone possède une flore vasculaire de 616 taxons. Sept espèces sont endémiques dans la mosaïque de forêts et de savanes des Plateaux Batéké. 17 espèces sont des suffrutices géoxyliques dépendants du feu, ce qui atteste des origines anciennes de ces savanes. Les feux favorisent le développement des espèces dépendantes du feu. Conclusion – L'objectif du PNPB est de créer un plan de gestion des feux culturellement adapté. La combinaison des feux coutumiers et des espèces adaptées au feu dans la savane crée une mosaïque de forêts et de savanes unique en Afrique centrale, qui mérite d'être protégée en même temps qu'est reconnu le rôle que jouent les populations Batéké-Alima dans le façonnage du paysage de la zone et sa gouvernance

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

A new species of Rhaptopetalum (Lecythidaceae) from south-western Gabon

Rhaptopetalum rabiense Kenfack & Nguema, sp. nov. from the Rabi forest in south-western Gabon is described, illustrated and assigned a provisional conservation status of “Critically Endangered”. An identification key to the five Gabonese species of Rhaptopetalum is also provided

Flora and fire in an old-growth Central African forest-savanna mosaic: a checklist of the Parc National des Plateaux Batéké (Gabon)

Background and aims – Old-growth savannas in Africa are impacted by fire, have endemic and geoxylic suffrutices, and are understudied. This paper explores the Parc National des Plateaux Batéké (PNPB) in Gabon and the impact of fire on its flora to understand if it is an old-growth savanna. It presents 1) a vascular plant checklist, including endemic species and geoxylic suffrutices and 2) an analysis of the impact of fire on the savanna herbaceous flora, followed by recommendations for fire management to promote plant diversity. Material and methods – 1,914 botanical collections from 2001–2019 collected by the authors and others were extracted from two herbaria databases in 2021 to create the checklist. The impact of fire was explored through a three season plot-based inventory of plant species (notably forbs and geoxylic suffrutices) in five annually, dry-season burned study areas located at 600 m in elevation. A two-factor ANOVA was conducted across two burn treatments and three season treatments. Key results – The area has a vascular flora of 615 taxa. Seven species are endemic to the Plateaux Batéké forest-savanna mosaic. Seventeen species are fire-dependent geoxylic suffrutices, attesting to the ancient origins of these savannas. Burning promotes fire-dependent species. Conclusion – The PNPB aims to create a culturally-adapted fire management plan. The combination of customary fire and fire-adapted species in the savanna creates a unique ancient forest-savanna mosaic in Central Africa that merits protection while recognising the role that the Batéké-Alima people have in shaping and governing this landscape

Flora and fire in an old-growth Central African forest-savanna mosaic: a checklist of the Parc National des Plateaux Batéké (Gabon)

Background and aims – Old-growth savannas in Africa are impacted by fire, have endemic and geoxylic suffrutices, and are understudied. This paper explores the Parc National des Plateaux Batéké (PNPB) in Gabon and the impact of fire on its flora to understand if it is an old-growth savanna. It presents 1) a vascular plant checklist, including endemic species and geoxylic suffrutices and 2) an analysis of the impact of fire on the savanna herbaceous flora, followed by recommendations for fire management to promote plant diversity. Material and methods – 1,914 botanical collections from 2001–2019 collected by the authors and others were extracted from two herbaria databases in 2021 to create the checklist. The impact of fire was explored through a three season plot-based inventory of plant species (notably forbs and geoxylic suffrutices) in five annually, dry-season burned study areas located at 600 m in elevation. A two-factor ANOVA was conducted across two burn treatments and three season treatments. Key results – The area has a vascular flora of 615 taxa. Seven species are endemic to the Plateaux Batéké forest-savanna mosaic. Seventeen species are fire-dependent geoxylic suffrutices, attesting to the ancient origins of these savannas. Burning promotes fire-dependent species. Conclusion – The PNPB aims to create a culturally-adapted fire management plan. The combination of customary fire and fire-adapted species in the savanna creates a unique ancient forest-savanna mosaic in Central Africa that merits protection while recognising the role that the Batéké-Alima people have in shaping and governing this landscape

Notes on cauliflory, sexual dimorphism and biogeography in Drypetes (Putranjivaceae, Malpighiales) and a taxonomic treatment for D. gabonensis and two new cauliflorous threatened species from Central Africa, D. aphanes sp. nov. and D. cauta sp. nov.

We present a preliminary discussion about cauliflory, sexual dimorphism and biogeographic patterns in Drypetes Vahl (Putranjivaceae Endl.), focused on Africa. We also present a taxonomic treatment for two new species of cauliflorous trees of this genus from the rainforests of western Central Africa, one endemic to Gabon and known from six gatherings, D. aphanes Quintanar, D.J.Harris & Barberá sp. nov., and the other distributed in Gabon and the Republic of the Congo, D. cauta D.J.Harris, Barberá & Quintanar sp. nov., also known from another six gatherings. They are presented along with D. gabonensis Pierre ex Hutch., known from 25 gatherings made throughout western Central Africa, a species with markedly dimorphic flowers between sexes compared to the rest of the species in the genus. Specimens of these two new species have been confused with D. gabonensis due to some morphological resemblances. This treatment includes the detailed descriptions of these three species, the typification of their names, a comparative table summarizing their main morphological differences, an identification key, an illustration and information about their habitat and distribution. A provisional IUCN Red List assessment shows that D. gabonensis and D. cauta sp. nov. are ‘Vulnerable’ species, and D. aphanes sp. nov. is ‘Endangered’. After the publication of these new species, Drypetes consists of 86 species in continental Africa and the Malagasy Region and 219 species for the whole world

Lurking in the Shadows: A New Species of Drypetes (Putranjivaceae) from Central Africa Hiding in Forest Plots and Herbaria

Here we publish a new species of forest tree of the genus Drypetes Vahl (Putranjivaceae), D. umbricola D. J. Harris & Quintanar, which has a wide distribution in Central Africa (Cameroon, Central African Republic, Democratic Republic of the Congo, Gabon, and Republic of the Congo). It is known from 70 herbarium collections and additional sterile plot vouchers. A differential diagnosis, detailed morphological description, photographs, an illustration, and information about its habitat, distribution, and conservation status are provided